Nanostructured titanium dioxide-based photocatalysts for self-cleaning concrete: аssessment of effects of phase composition on photocatalytic activity of TiO2
Introduction. Currently, the development of photocatalytically active cement-based materials with self-cleaning properties is a promising area of building materials science. Self-cleaning concrete is obtained by using photocatalytic additives, of which titanium dioxide (TiO2 ) is the most co...
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| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
OOO "CNT «NanoStroitelstvo»
2025-06-01
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| Series: | Нанотехнологии в строительстве |
| Subjects: | |
| Online Access: | https://nanobuild.ru/en_EN/journal/Nanobuild-3-2025/307-324.pdf |
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| Summary: | Introduction. Currently, the development of photocatalytically active cement-based materials with self-cleaning properties is
a promising area of building materials science. Self-cleaning concrete is obtained by using photocatalytic additives, of which
titanium dioxide (TiO2
) is the most common. It has been found that the functional properties of TiO2
depend largely on its phase
composition. This study aimed to establish the patterns of influence of phase composition on the photocatalytic activity of titanium
dioxide under the impact of artificial ultraviolet and natural solar radiation and to identify the most effective titanium oxide-based
photocatalysts for subsequent use in the composition of self-cleaning concrete. Methods and materials. Four titanium dioxide
samples, namely two industrial samples and two samples synthesized by hydrolysis of titanium alkoxide in acidified water-alcoholic
medium followed by calcination at 500 °C, were the objects of the study. X-ray powder diffractometry was the method used to
investigate the structure parameters of TiO2
samples. The model reaction of oxidative degradation of methylene blue under UV- and
daylight exposure was the means for studying the photocatalytic activity of titanium dioxide samples. Results and discussion.
It was found that polymorphic modifications of titanium dioxide had a multidirectional effect on its functional characteristics, in
particular, a rise in the content of anatase and rutile led to an increase and decrease in the photoactivity of TiO2
samples, respectively.
The single-phase sample with anatase structure was most effective under UV irradiation, while the three-phase sample with the
anatase : brookite : rutile ratio of 67% : 13% : 20% had the highest activity under daylight exposure. The photocatalyst composition,
including several polymorphs of TiO2
with a predominance of anatase form (more than 50%), allowed to achieve a synergistic effect
of increasing the photocatalytic activity of titanium dioxide under conditions of solar radiation due to the formation of type-II semi
conductor heterojunctions. Heterostructures made it possible to improve the spatial separation of charge carriers and to reduce the
recombination rate of photogenerated electron-hole pairs. Conclusion. The obtained results indicated the possibility of improving
the functional characteristics of titanium oxide-based additives for self-cleaning concrete due to the targeted regulation of their
phase composition by optimizing the synthesis parameters of photocatalytic modifiers. |
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| ISSN: | 2075-8545 |